How do iscoms prime immune response?
The depot effect is considered an important function of adjuvants by trapping the antigen to the site of administration and to attract cells of various kinds, including APC. Examples of such adjuvants are aluminium hydroxide, oil adjuvants, which are biodegradable microspheres (e.g. polylactide co-glucolide (PLG) spheres).8 In contrast to those, the iscom is fast removed from the site of injection to the draining lymphatic system. After intraperitoneal (i.p.) injection of influenza virus iscoms, an increased amount of the radiolabelled antigen was found in the spleen for a prolonged period of time compared to when the same amount of antigen was administered by i.p. injection as protein micelles.8 It can be speculated that iscoms target antigens to follicular dendritic cells in the spleen more efficiently than micelles, which would be an alternative depot effect.The uptake of antigen by APC is an early event in the initiation of an immune response. Villacres et al.10 showed that influen
